(1) Field of the Invention
The invention relates to an optoelectronic detector assembly comprising a cooling device connected with a detector in a heat-conducting relationship, and a procedure for the operation of such a detector assembly.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Optoelectronic detectors, for example, semiconductor optoelectronic detectors as in the case of charge coupled devices (CCD) or secondary electron emission optoelectronic detectors as in the case of photo multipliers (PMT), have a temperature-dependent dark current that causes a hissing noise. The dark current can be reduced through cooling so that the measurable dynamic range will be increased. To prevent any undesired condensation of humidity on the detector through the cooling process (bedewing), at the current state of the art the detector including the cooling device is typically encapsulated in a Peltier element, an airtight housing, that is filled with a dried gas or emptied. The waste heat of the cooling device may be fed to a cooling element connected with the cooler in heat-conducting fashion and/or be used to heat other structural elements, for example an entry window of the housing. However, airtight encapsulation is expensive.
U.S. Pat. No. 7,382,531 B2 teaches arranging a high humidity space for a living specimen in front of a microscopic lens and heating the front lens of the object lens by means of a heating device to a temperature above the dew point temperature of the high humidity space in order to prevent a bedewing of the front lens. However, heating an optoelectronic detector is out of the question due to the higher dark current created thereby.
The invention is based on the objective of indicating an improved detector assembly of the type mentioned at the beginning that can be manufactured and be used at low cost.